Magnolia 'Little Gem'-easily controlled to te height range that suits your requirements ben. Will generally form a clipped block of foliage over time though not as dense as the lilly pilly we chatted about. *Could be used as a "pleached" hedge(st
Laurel HedgeLaurel is the quickest growing evergreen shrub, so if you don't want a conifer hedge, Laurel is the quickest and cheapest way of creating an evergreen garden hedge. Laurels will also provide the most instant hedging as the taller sizes
I'd use flowering shrubs rather than evergreens, a few different kinds, and arrange them in a reverse symmetry.] A long, thin garden with plenty of room for puppy to play and lots of privacy from the neighbours.